Actinic ray-sensitive or radiation-sensitive composition, method for purifying actinic ray-sensitive or radiation-sensitive composition, pattern forming method, and method for manufacturing electronic device

ABSTRACT

An actinic ray-sensitive or radiation-sensitive composition contains a cation including a metal atom and a ligand, in which the number of particles in liquid having particle diameters of 0.15 μm or less included in 1 mL of the actinic ray-sensitive or radiation-sensitive composition is 10 or less.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2017/9652, filed on Mar. 10, 2017, which claims priority under 35U.S.C. § 119(a) to Japanese Patent Application No. 2016-060952, filed onMar. 24, 2016. Each of the above application(s) is hereby expresslyincorporated by reference, in its entirety, into the presentapplication.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to an actinic ray-sensitive orradiation-sensitive composition, a method for purifying an actinicray-sensitive or radiation-sensitive composition, a pattern formingmethod, and a method for manufacturing an electronic device.

More specifically, the present invention relates to an actinicray-sensitive or radiation-sensitive composition which can be used for aprocess for manufacturing a semiconductor such as an integrated circuit(IC), a process for manufacturing a circuit board for a liquid crystal,a thermal head, or the like, and other lithographic processes ofphotofabrication, a method for purifying an actinic ray-sensitive orradiation-sensitive composition, a pattern forming method, and a methodfor manufacturing an electronic device.

2. Description of the Related Art

In processes for manufacturing semiconductor devices such as anintegrated circuit (IC) and a large scale integrated circuit (LSI) inthe related art, microfabrication by lithography using a resistcomposition has been carried out.

Formation of an ultrafine pattern in a submicron region or aquarter-micron region has been demanded in accordance with realizationof high integration for integrated circuits. With such a demand,exposure has been performed using g-rays in the related art, but it isnow performed using i-rays, and further, as with an excimer laser light(KrF and ArF), a tendency that an exposure wavelength becomes shorter isobserved. Moreover, developments in lithography using electron beams(EB), X-rays, or extreme ultraviolet rays (EUV), in addition to theexcimer laser light, have also been currently proceeding.

Under such circumstances, various configurations have been proposed fora resist composition, and for example, JP2011-253185A describes atechnique for forming a pattern using a resist composition includingwater, a metal suboxide cation, a polyatomic inorganic anion, and aligand including a peroxide group. Further, US2015/0056542A describes atechnique for forming a pattern using a resist composition including ametal cation, an organic ligand, and an organic solvent.

SUMMARY OF THE INVENTION

However, with the techniques described in JP2011-253185A andUS2015/0056542A, deterioration in resolution of a pattern and generationof residual defects occur in a case where foreign matters havingchemically or physically different characteristics remain even in smallamounts in a resist composition, in particular, in the formation of anultrafine pattern (for example, a pattern with a line width of 20 nm orless).

Therefore, an object of the present invention is to provide an actinicray-sensitive or radiation-sensitive composition capable of forming apattern having excellent resolution and few residual defects, inparticular, in the formation of an ultrafine pattern (for example, apattern with a line width of 20 nm or less), a method for purifying anactinic ray-sensitive or radiation-sensitive composition, a patternforming method including the method for purifying an actinicray-sensitive or radiation-sensitive composition, and a method formanufacturing an electronic device.

The present inventors have conducted studies, and as a result, they havediscovered that it is possible to accomplish the objects by thefollowing means.

<1> An actinic ray-sensitive or radiation-sensitive compositioncomprising:

a cation including a metal atom; and

a ligand,

in which the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition is 10 or less.

<2> The actinic ray-sensitive or radiation-sensitive composition asdescribed in <1>,

in which the actinic ray-sensitive or radiation-sensitive compositioncontains a suboxide cation of a metal atom, a counter anion, aperoxide-based ligand, and water.

<3> The actinic ray-sensitive or radiation-sensitive composition asdescribed in <1>,

in which the actinic ray-sensitive or radiation-sensitive compositioncontains the cation including a metal atom, an organic ligand, and anorganic solvent.

<4> The actinic ray-sensitive or radiation-sensitive composition asdescribed in any one of <1> to <3>,

in which the metal atom is at least one selected from hafnium,zirconium, and tin.

<5> The actinic ray-sensitive or radiation-sensitive composition asdescribed in any one of <1> to <4>,

in which the metal atom is at least one selected from hafnium andzirconium.

<6> The actinic ray-sensitive or radiation-sensitive composition asdescribed in any one of <1> to <4>,

in which the metal atom is tin.

<7> A method for purifying an actinic ray-sensitive orradiation-sensitive composition, comprising subjecting a solution of anactinic ray-sensitive or radiation-sensitive composition containing acation including a metal atom and a ligand to circulation filtrationusing a filter of a polyethylene-based resin,

in which the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition after the circulation filtration is 10or less.

<8> The method for purifying an actinic ray-sensitive orradiation-sensitive composition as described in <7>,

in which the circulation filtration is performed using a filter of apolyamide-based resin in combination with the filter of apolyethylene-based resin.

<9> The method for purifying an actinic ray-sensitive orradiation-sensitive composition as described in <7> or <8>,

in which a pore diameter of the filter of a polyethylene-based resin is10 nm or less.

<10> A pattern forming method comprising the method for purifying anactinic ray-sensitive or radiation-sensitive composition as described inany one of <7> to <9>.

<11> A method for manufacturing an electronic device, comprising thepattern forming method as described in <10>.

According to the present invention, it is possible to provide an actinicray-sensitive or radiation-sensitive composition capable of forming apattern having excellent resolution and few residual defects, inparticular, in the formation of an ultrafine pattern (for example, apattern with a line width of 20 nm or less), a method for purifying anactinic ray-sensitive or radiation-sensitive composition, a patternforming method including the method for purifying an actinicray-sensitive or radiation-sensitive composition, and a method formanufacturing an electronic device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view for describing a filtration device.

FIG. 2 is a schematic view for describing a filtration device.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, aspects of the present invention will be described.

Furthermore, in citations for a group (atomic group) in the presentspecification, in a case where the group (atomic group) is denotedwithout specifying whether it is substituted or unsubstituted, the groupincludes both a group (atomic group) having no substituent and a group(atomic group) having a substituent. For example, an “alkyl group”includes not only an alkyl group having no substituent (unsubstitutedalkyl group), but also an alkyl group having a substituent (substitutedalkyl group).

“Actinic rays” or “radiation” in the present specification means, forexample, a bright line spectrum of a mercury lamp, far ultraviolet raystypified by an excimer laser, extreme ultraviolet rays, X-rays, electronbeams, or the like. In the present invention, light means actinic raysor radiation. “Exposure” in the present specification includes, unlessotherwise specified, not only exposure using a bright line spectrum of amercury lamp, far ultraviolet rays typified by an excimer laser, X-rays,extreme ultraviolet rays, or the like, but also lithography by particlerays such as electron beams and ion beams.

In the present specification, a “(meth)acrylic monomer” means at leastone of monomers having a structure of “CH₂═CH—CO—” or “CH₂═C(CH₃)—CO—”.Similarly, “(meth)acrylate” and “(meth)acrylic acid” mean “at least oneof acrylate or methacrylate” and “at least one of acrylic acid ormethacrylic acid”, respectively.

In the present specification, the numerical ranges shown with “to” areused to mean ranges including the numerical values indicated before andafter “to” as lower limit values and upper limit values, respectively.

[Actinic Ray-Sensitive or Radiation-Sensitive Composition]

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention is an actinic ray-sensitive or radiation-sensitivecomposition containing a cation including a metal atom and a ligand, inwhich the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition is 10 or less.

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention is not particularly limited, but is preferably aresist composition.

The actinic ray-sensitive or radiation-sensitive composition in thepresent invention is preferably for exposure using electron beams orextreme ultraviolet rays, and more preferably for exposure using extremeultraviolet rays.

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention is preferably an actinic ray-sensitive orradiation-sensitive composition in any one aspect of (A) or (B).

(A) An actinic ray-sensitive or radiation-sensitive compositioncontaining a suboxide cation (a1) of a metal atom, a counter anion (a2),a peroxide-based ligand (a3), and water (a4).

(B) An actinic ray-sensitive or radiation-sensitive compositioncontaining a cation (b1) including a metal atom, an organic ligand (b2),and an organic solvent (b3).

The actinic ray-sensitive or radiation-sensitive composition in theaspect of (A) is also referred to as an “actinic ray-sensitive orradiation-sensitive composition (A)”.

The actinic ray-sensitive or radiation-sensitive composition in theaspect of (B) is also referred to as an “actinic ray-sensitive orradiation-sensitive composition (B)”.

{Actinic Ray-Sensitive or Radiation-Sensitive Composition (A)}

The actinic ray-sensitive or radiation-sensitive composition in theaspect of (A) will be described.

<Suboxide Cation (a1) of Metal Atom>

As the suboxide cation (metal suboxide cation) (a1) of a metal atomincluded in the actinic ray-sensitive or radiation-sensitive composition(A), for example, VO²⁺, SbO⁺, ReO₃ ⁺, TiO²⁺, TaO³⁺, TaO₂ ⁺, YO⁺, NbO²⁺,MoO²⁺, WO⁴⁺, WO₂ ²⁺, AlO⁺, GaO⁺, CrO⁺, FeO⁺, BiO⁺, LaO⁺, CeO⁺, PrO⁺,NdO⁺, PmO⁺, SmO⁺, EuO⁺, GdO⁺, TbO⁺, DyO⁺, HoO⁺, ErO⁺, TmO⁺, YbO⁺, LuO⁺,TiO_(y)(OH)_(z) ^((4−2y−z)+), TaO_(y)(OH)_(z) ^((5−2y−z)+),YO_(y)(OH)_(z) ^((3−2y−z)+), NbO_(y)(OH)_(z) ^((4−2y−z)+),MOO_(y)(OH)_(z) ^((4−2y−z)+), WO_(y)(OH)_(z) ^((6−2y−z)+),AlO_(y)(OH)_(z) ^((3−2y−z)+), GaO_(y)(OH)_(z) ^((3−2y−z)+), Zn(OH)⁺,CrO_(y)(OH)_(z) ^((3−2y−z)+), FeO_(y)(OH)_(z) ^((3−2y−z)+),BiO_(y)(OH)_(z) ^((3−2y−z)+), LaO_(y)(OH)_(z) ^((3−2y−z)+),CeO_(y)(OH)_(z) ^((3−2y−z)+), PrO_(y)(OH)_(z) ^((3−2y−z)+),NbO_(y)(OH)_(z) ^((3−2y−z)+), PmO_(y)(OH)_(z) ^((3−2y−z)+),SmO_(y)(OH)_(z) ^((3−2y−z)+), EuO_(y)(OH)_(z) ^((3−2y−z)+),GdO_(y)(OH)_(z) ^((3−2y−z)+), TbO_(y)(OH)_(z) ^((3−2y−z)+),DyO_(y)(OH)_(z) ^((3−2y−z)+), HoO_(y)(OH)_(z) ^((3−2y−z)+),ErO_(y)(OH)_(z) ^((3−2y−z)+), TmO_(y)(OH)_(z) ^((3−2y−z)+),YbO_(y)(OH)_(z) ^((3−2y−z)+), LuO_(y)(OH)_(z) ^((3−2y−z)+), ZrO²⁺,ZrOOH⁺, Zr(OH)₂ ²⁺, Zr(OH)₃ ⁺, HfO²⁺, HfOOH⁺, Hf(OH)₂ ²⁺, Hf(OH)₃ ⁺, ora combination thereof can be used. The parameters y and z can beselected such that the ions are electrostatic based on the specificoxidation states of the metal atoms.

As a preferred metal suboxide cation, a metal suboxide cation having atleast one selected from hafnium and zirconium is preferable, and a metalsuboxide cation including hafnium is more preferable. Examples thereofinclude ZrO²⁺, ZrOOH⁺, Zr(OH)₂ ²⁺, Zr(OH)₃ ⁺, HfO²⁺, HfOOH⁺, Hf(OH)₂ ²⁺,Hf(OH)₃ ⁺, a combination thereof, and/or a combination thereof withanother metal suboxide cation.

Furthermore, the actinic ray-sensitive or radiation-sensitivecomposition (A) can further include a metal cation, for example, hafnium(Hf+), titanium (Ti⁴⁺), zirconium (Zr⁴⁺), cerium (Ce⁴⁺), tin (Sn⁴⁺),tantalum (Ta⁵⁺), niobium (Nb⁴⁺), yttrium (Y³⁺), molybdenum (Mo⁶⁺),tungsten (W⁶⁺), aluminum (Al³⁺), gallium (Ga³⁺), zinc (Zn²⁺), chromium(Cr³⁺), iron (Fe³⁺), bismuth (Bi³⁺), scandium (Sc³⁺), vanadium (V⁴⁺),manganese (Mn²⁺, Mn³⁺, Mn⁴⁺), cobalt (Co²⁺, Co³⁺), nickel (Ni²⁺, Ni³⁺),indium (In³⁺), antimony (Sb⁵⁺), iridium (Ir³⁺, Ir⁴⁺), platinum (Pt²⁺,Pt⁴⁺), lanthanum (La³⁺), praseodymium (Pr³⁺), neodymium (Nd³⁺),promethium (Pm³⁺), samarium (Sm³⁺), europium (Eu³⁺), gadolinium (Gd³⁺),terbium (Tb³⁺), dysprosium (Dy³⁺), holmium (Ho³⁺), erbium (Er³⁺),thulium (Tm³⁺), ytterbium (Yb³⁺), lutetium (Lu³⁺), or a combinationthereof.

The content ratio of the metal suboxide cation (a1) in the actinicray-sensitive or radiation-sensitive composition (A) is preferably from0.01 mol/L to 1.4 mol/L, more preferably from 0.05 mol/L to 1.2 mol/L,and still more preferably from 0.1 mol/L to 1.0 mol/L.

The metal suboxide cation (a1) can be used in the form of a salt such asa halogen salt (for example, fluoride, bromide, iodide, or a combinationthereof).

<Counter Anion (a2)>

The counter anion (a2) included in the actinic ray-sensitive orradiation-sensitive composition (A) may be, for example, either aninorganic anion or an organic anion. Specific examples thereof include ahydroxide ion, a halogen anion (for example, a fluoride ion, a chlorideion, a bromide ion, and an iodide ion), a substituted or unsubstitutedalkylcarboxylic acid ion (for example, an acetate ion and atrifluoroacetate ion), a substituted or unsubstituted aryl carboxylateion (for example, a benzoate ion), a substituted or unsubstitutedalkylsulfonate ion (for example, a methanesulfonate ion and atrifluoromethanesulfonate ion), a substituted or unsubstitutedarylsulfonate ion (for example, a para-toluenesulfonate ion and apara-dichlorobenzenesulfonate ion), an aryldisulfonate ion (for example,a 1,3-benzenedisulfonate ion, a 1,5-naphthalenedisulfonate ion, and a2,6-naphthalenedisulfonate ion), an alkylsulfate ion (for example, amethylsulfate ion), a sulfate ion, a thiocyanate ion, a nitrate ion, aperchlorate ion, a tetrafluoroborate ion, a tetraarylborate ion, atetrakis(pentafluorophenyl)borate ion (B⁻(C₆F₅)₄), a hexafluorophosphateion, a picrate ion, an amide ion (including an amide substituted with anacyl group or a sulfonyl group), and a methide ion (including a methidesubstituted with an acyl group or a sulfonyl group).

The counter anion is preferably a counter anion including an oxygenatom, and more preferably a sulfate ion.

The content ratio of the counter anion (a2) in the actinic ray-sensitiveor radiation-sensitive composition (A) is preferably from 0.5 times to2.0 times, more preferably from 0.75 times to 1.5 times, and still morepreferably from 0.8 times to 1.3 times the content ratio of the metalsuboxide cation (a1), on a molar basis.

Moreover, the actinic ray-sensitive or radiation-sensitive composition(A) may include a polyatomic anion which is oxygen-based. Through theformation of a final inorganic oxide, the oxygen-based polyatomic anioncan be brought into an oxide in final solid materials. In a similarmanner to a case of the cation, the properties of these anions can bedependent on a pH. Examples of the oxygen-based polyatomic anion includeSO₄ ²⁻, BO₃ ³⁻, AsO₄ ³⁻, MoO₄ ²⁻, PO₄ ³⁻, WO₄ ²⁻, Sea₄ ²⁻, SiO₄ ⁴⁻, aprotonated form thereof, and a combination thereof. The molarconcentration of the polyatomic anions in the actinic ray-sensitive orradiation-sensitive composition (A) is preferably about 0.5 to about 2.0times, more preferably about 0.75 to about 1.5 times, and still morepreferably about 0.8 to about 1.3 times the molar concentration of thesuboxide cation (a1) of a metal atom. The polyatomic anion may be addedas an acid in a case where pH adjustment is suitable, or may also beadded together with a desired metal cation. The actinic ray-sensitive orradiation-sensitive composition (A) can be prepared into a state that itincludes an anion such as a halogen anion which may also be addedtogether with the suboxide cation (a1) of a metal atom. The halogenanion can be reacted with the peroxide-based ligand (a3) to form ahalogen molecule such as Cl₂, Br₂, and I₂. The reaction with the halogenanion reduces the peroxide concentration to an amount which isappropriate to the amount of the peroxide added.

In addition, it is also preferable that the actinic ray-sensitive orradiation-sensitive composition (A) contains a counter anion which issoluble in an organic solvent as the counter anion (a2). Examples of thecounter anion which is soluble in an organic solvent include atrifluoromethanesulfonic acid and PF₆ ⁻.

<Peroxide-Based Ligand (a3)>

The peroxide-based ligand (a3) included in the actinic ray-sensitive orradiation-sensitive composition (A) preferably has a peroxide group(—O—O—), and is more preferably a hydrogen peroxide. Further, aninorganic peroxide-based ligand can also be used as the peroxide-basedligand (a3). Examples of the inorganic peroxide-based ligand include aperoxysulfate ion (SO₅H⁻), a peroxydisulfate ion (S₂O₈ ²⁻), aperoxychlorate ion (ClO₅H⁻), and a combination thereof.

The content ratio of the peroxide-based ligand (a3) in the actinicray-sensitive or radiation-sensitive composition (A) is preferably from0.5 times to 25 times, more preferably from 2 times to 25 times, stillmore preferably from 3 times to 25 times, particularly preferably from 4times to 25 times, and most preferably from 5 times to 25 times thecontent ratio of the metal suboxide cation (a1), on a molar basis.

As the concentration of the peroxide-based ligand (a3) is higher, thestability of the actinic ray-sensitive or radiation-sensitivecomposition (A) is more excellent. The actinic ray-sensitive orradiation-sensitive composition (A) can be stabilized against thesedimentation of a solid matter for at least 2 hours while furtherstirring, and in some cases, can be stabilized for a significantly longperiod of time such as 1 month or more. As described above, as theperoxide-based ligand (a3), a hydrogen peroxide is preferable, but otherinorganic peroxides are suitable in some cases. Further, in anotheraspect, organic peroxides can be used.

<Water (a4)>

As the water (a4) included in the actinic ray-sensitive orradiation-sensitive composition (A), ultrapure water is preferable.

A method for preparing the actinic ray-sensitive or radiation-sensitivecomposition (A) is not particularly limited, but a method in which asolution including the metal suboxide cation (a1), a solution includingthe counter anion (a2), and a solution including the peroxide-basedligand (a3) are individually prepared and then mixed is preferable. Itis preferable that the solution including the metal suboxide cation (a1)is mixed with the solution including the peroxide-based ligand (a3) suchthat the peroxide-based ligand (a3) coordinates to the metal suboxidecation (a1), and the mixture is left to be stabilized for a certainperiod of time (for example, 5 minutes to 15 minutes), and then mixedwith the solution including the counter anion (a2).

{Actinic Ray-Sensitive or Radiation-Sensitive Composition (B)}

Next, the actinic ray-sensitive or radiation-sensitive composition inthe aspect of (B) will be described.

<Cation (b1) Including Metal Atom>

The cation (b1) including a metal atom included in the actinicray-sensitive or radiation-sensitive composition (B) is preferably acation (metal cation) of a metal atom, more preferably a cation of atleast one metal selected from hafnium, zirconium, tin, antimony, andindium, still more preferably a cation of at least one metal selectedfrom hafnium, zirconium, and tin, and particularly preferably a cationof tin. Further, as other metal cations, a cation of at least one atomselected from titanium, zirconium, hafnium, vanadium, cobalt,molybdenum, tungsten, aluminum, gallium, silicon, germanium, phosphorus,arsenic, yttrium, lanthanum, cesium, and lutetium may be included.

<Organic Ligand (b2)>

Examples of the organic ligand (b2) included in the actinicray-sensitive or radiation-sensitive composition (B) include an alkylgroup (for example, a methyl group, an ethyl group, a propyl group, abutyl group, and a t-butyl group), an aryl group (for example, a phenylgroup), an aralkyl group (for example, a benzyl group), an alkenyl group(for example, a vinyl group and an allyl group), and a carboxylic ester(for example, an acetic ester, a propionic ester, a butanoic ester, anda benzoic ester).

The content ratio of the organic ligand (b2) in the actinicray-sensitive or radiation-sensitive composition (B) is preferably from0.25 times to 4 times, more preferably from 0.5 times to 3.5 times,still more preferably from 0.75 times to 3 times, and particularlypreferably from 1 time to 2.75 times the content ratio of the cation(b1) including a metal atom, on a molar basis.

<Organic Solvent (b3)>

Examples of the organic solvent (b3) included in the actinicray-sensitive or radiation-sensitive composition (B) include an aromaticsolvent (for example, xylene and toluene), an ester-based solvent (forexample, propylene glycol monomethyl ether acetate, ethyl acetate, andethyl lactate), an alcohol-based solvent (for example,2-methyl-2-propanol, 4-methyl-2-pentanol, 1-propanol, 1-butanol,anisole), and a ketone-based solvent (for example, methyl ethyl ketone).

The flash point of the organic solvent (b3) is preferably 10° C. orhigher, more preferably 20° C. or higher, and still more preferably 25°C. or higher.

The vapor pressure of the organic solvent (b3) at 20° C. is preferably10 kPa or less, more preferably 8 kPa or less, and still more preferably6 kPa or less.

The content ratio of the organic solvent (b3) in the actinicray-sensitive or radiation-sensitive composition (B) is preferably 5 to1,000 g, and more preferably 10 to 1,000 g, with respect to 1 g of thetotal solid content of the actinic ray-sensitive or radiation-sensitivecomposition (B).

[Number of Particles in Liquid]

The number of particles in liquid having particle diameters of 0.15 μmor less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition of the present invention is 10 or less,preferably 7 or less, more preferably 5 or less, and still morepreferably 3 or less.

It is considered that in a case where the number of particles in liquidhaving particle diameters of 0.15 μm or less included in 1 mL of theactinic ray-sensitive or radiation-sensitive composition of the presentinvention is 10 or less, it is possible to form a pattern havingexcellent resolution and few residual defects, in particular, in theformation of an ultrafine pattern (for example, a pattern with a linewidth of 20 nm or less).

The number of particles in liquid having particle diameters of 0.15 μmor less can be measured, for example, using a particle counted using aparticle counter KS-41 manufactured by Rion Co., Ltd.

Examples of a method for setting the number of particles in liquidhaving particle diameters of 0.15 μm or less included in 1 mL of theactinic ray-sensitive or radiation-sensitive composition of the presentinvention to 10 or less include the method for purifying an actinicray-sensitive or radiation-sensitive composition of the presentinvention, which will be described later.

<Basic Compound>

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention may contain a basic compound. By incorporation of thebasic compound, the stability of the actinic ray-sensitive orradiation-sensitive composition is improved.

Preferred examples of the basic compound include compounds havingstructures represented by Formulae (A) to (E).

In General Formula (A), R²⁰⁰, R²⁰¹, and R²⁰² may be the same as ordifferent from each other, and each independently represent a hydrogenatom, an alkyl group (preferably having 1 to 20 carbon atoms), acycloalkyl group (preferably having 3 to 20 carbon atoms), or an arylgroup (preferably having 6 to 20 carbon atoms), and R²⁰¹ and R²⁰² may bebonded to each other to form a ring.

With regard to the alkyl group, the alkyl group having a substituent ispreferably an aminoalkyl group having 1 to 20 carbon atoms, ahydroxyalkyl group having 1 to 20 carbon atoms, or a cyanoalkyl grouphaving 1 to 20 carbon atoms.

In General Formula (E), R²⁰³, R²⁰⁴, R²⁰⁵, and R²⁰⁶ may be the same as ordifferent from each other, and each independently represent an alkylgroup having 1 to 20 carbon atoms.

The alkyl group in General Formulae (A) and (E) may have a substituentor may be not substituted.

It is more preferable that the alkyl groups in General Formulae (A) and(E) are unsubstituted.

Preferred examples of the compound include guanidine, aminopyrrolidine,pyrazole, pyrazoline, piperazine, aminomorpholine, aminoalkylmorpholine,and piperidine, and more preferred examples of the compound include acompound having an imidazole structure, a diazabicyclo structure, anonium hydroxide structure, an onium carboxylate structure, atrialkylamine structure, an aniline structure, or a pyridine structure,an alkylamine derivative having a hydroxyl group and/or an ether bond,and an aniline derivative having a hydroxyl group and/or an ether bond.

Examples of the compound having an imidazole structure includeimidazole, 2,4,5-triphenylimidazole, and benzimidazole. Examples of thecompound having a diazabicyclo structure include1,4-diazabicyclo[2,2,2]octane, 1,5-diazabicyclo[4,3,0]nona-5-ene, and1,8-diazabicyclo[5,4,0]undeca-7-ene. Examples of the compound having anonium hydroxide structure include triarylsulfonium hydroxide,phenacylsulfonium hydroxide, sulfonium hydroxide having 2-oxoalkylgroup, and specifically triphenylsulfonium hydroxide,tris(t-butylphenyl)sulfonium hydroxide, bis(t-butylphenyl)iodoniumhydroxide, phenacylthiophenium hydroxide, and 2-oxopropylthiopheniumhydroxide. The compound having an onium carboxylate structure is acompound in which the anion moiety of the compound having an oniumhydroxide structure becomes a carboxylate, and examples thereof includeacetate, adamantane-1-carboxylate, and perfluoroalkyl carboxylate.Examples of the compound having a trialkylamine structure includetri(n-butyl)amine and tri(n-octyl)amine. Examples of the compound havingan aniline structure include 2,6-diisopropylaniline,N,N-dimethylaniline, N,N-dibutylaniline, and N,N-dihexylaniline.Examples of the alkylamine derivative having a hydroxyl group and/or anether bond include ethanolamine, diethanolamine, triethanolamine, andtris(methoxyethoxyethyl)amine. Examples of the aniline derivative havinga hydroxyl group and/or an ether bond includeN,N-bis(hydroxyethyl)aniline.

Preferred examples of the basic compound include an amine compoundfurther having a phenoxy group and an ammonium salt compound having aphenoxy group.

As the amine compound, a primary, secondary, or tertiary amine compoundcan be used, and an amine compound having at least one alkyl groupbonded to the nitrogen atom thereof is preferable. The amine compound ismore preferably a tertiary amine compound. In the amine compound, aslong as at least one alkyl group (preferably having 1 to 20 carbonatoms) is bonded to the nitrogen atom, a cycloalkyl group (preferablyhaving 3 to 20 carbon atoms) or an aryl group (preferably having 6 to 12carbon atoms) other than the alkyl group may be bonded to the nitrogenatom.

Incidentally, it is preferable that the amine compound has an oxygenatom in the alkyl chain thereof, thereby forming an oxyalkylene group.The number of oxyalkylene groups per molecule may be 1 or more, and ispreferably 3 to 9, and more preferably 4 to 6. The oxyalkylene group ispreferably an oxyethylene group (—CH₂CH₂O—) or an oxypropylene group(—CH(CH₃)CH₂O— or —CH₂CH₂CH₂O—), and more preferably an oxyethylenegroup.

As the ammonium salt compound, a primary, secondary, tertiary, orquaternary ammonium salt compound can be used. An ammonium salt compoundhaving at least one alkyl group bonded to the nitrogen atom thereof ispreferable. In the ammonium salt compound, as long as at least one alkylgroup (preferably having 1 to 20 carbon atoms) is bonded to the nitrogenatom, a cycloalkyl group (preferably having 3 to 20 carbon atoms) or anaryl group (preferably having 6 to 12 carbon atoms) other than the alkylgroup may be bonded to the nitrogen atom.

It is preferable that the ammonium salt compound has an oxygen atom inan alkyl chain thereof, thereby forming an oxyalkylene group. The numberof oxyalkylene groups per molecule may be 1 or more, and is preferably 3to 9, and more preferably 4 to 6. The oxyalkylene group is preferably anoxyethylene group (—CH₂CH₂O—) or an oxypropylene group (—CH(CH₃)CH₂O— or—CH₂CH₂CH₂O—), and more preferably an oxyethylene group.

Examples of the anion in the ammonium salt compound include a halogenatom, sulfonate, borate, and phosphate. Among those, a halogen atom andsulfonate are preferable. Among the halogen atoms, chloride, bromide,and iodide are particularly preferable. Among the sulfonates, an organicsulfonate having 1 to 20 carbon atoms is particularly preferable.Examples of the organic sulfonate include aryl sulfonate and alkylsulfonate having 1 to 20 carbon atoms. The alkyl group in the alkylsulfonate may have a substituent. Examples of the substituent includefluorine, chlorine, bromine, an alkoxy group, an acyl group, and an arylgroup. Specific examples of the alkyl sulfonate include methanesulfonate, ethane sulfonate, butane sulfonate, hexane sulfonate, octanesulfonate, benzyl sulfonate, trifluoromethane sulfonate,pentafluoroethane sulfonate, and nonafluorobutane sulfonate. Examples ofthe aryl group in the aryl sulfonate include a benzene ring, anaphthalene ring, and an anthracene ring. The benzene ring, thenaphthalene ring, or the anthracene ring may have a substituent.Preferred examples of the substituent include a linear or branched alkylgroup having 1 to 6 carbon atoms and a cycloalkyl group having 3 to 6carbon atoms. Specific examples of the linear or branched alkyl groupand the cycloalkyl group include methyl, ethyl, n-propyl, isopropyl,n-butyl, i-butyl, t-butyl, n-hexyl, and cyclohexyl. Other examples ofthe substituent include an alkoxy group having 1 to 6 carbon atoms, ahalogen atom, cyano, nitro, an acyl group, and an acyloxy group.

The amine compound with a phenoxy group and the ammonium salt compoundwith a phenoxy group are those having a phenoxy group at the end of thealkyl group of each of the amine compound and the ammonium salt compoundopposite to the nitrogen atom. The phenoxy group may have a substituent.Examples of the substituent of the phenoxy group include an alkyl group,an alkoxy group, a halogen atom, a cyano group, a nitro group, acarboxyl group, a carboxylic ester group, a sulfonic ester group, anaryl group, an aralkyl group, an acyloxy group, and an aryloxy group.The position of the substituent may be any of 2- to 6-positions. Thenumber of the substituents may be any in a range of 1 to 5.

It is preferable that at least one oxyalkylene group is containedbetween the phenoxy group and the nitrogen atom. The number ofoxyalkylene groups per molecule may be 1 or more, and is preferably 3 to9, and more preferably 4 to 6. The oxyalkylene group is preferably anoxyethylene group (—CH₂CH₂O—) or an oxypropylene group (—CH(CH₃)CH₂O— or—CH₂CH₂CH₂O—), and more preferably an oxyethylene group.

The amine compound having a phenoxy group can be obtained by heating aprimary or secondary amine having a phenoxy group with a haloalkyl etherto make a reaction, and then adding an aqueous solution of a strong basesuch as sodium hydroxide, potassium hydroxide, and tetraalkylammoniumthereto, followed by extraction with an organic solvent such as ethylacetate and chloroform. Alternatively, the amine compound having aphenoxy group can be obtained by heating a primary or secondary aminewith a haloalkyl ether having a phenoxy group at a terminal thereof tomake a reaction, and then adding an aqueous solution of a strong basesuch as sodium hydroxide, potassium hydroxide, and tetraalkylammoniumthereto, followed by extraction with an organic solvent such as ethylacetate and chloroform.

As the basic compound, for example, the compounds (amine compounds,amide group-containing compounds, urea compounds, nitrogen-containingheterocycle compounds, and the like) described in paragraphs 0140 to0144 of JP2013-11833A can be used.

<Ultraviolet Absorber>

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention may contain an ultraviolet absorber. By incorporationof the ultraviolet absorber, the stability of the actinic ray-sensitiveor radiation-sensitive composition is improved. The ultraviolet absorberis preferably a conjugated diene-based compound, and more preferably acompound represented by General Formula (UV).

In General Formula (UV), R¹ and R² each independently represent ahydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an arylgroup having 6 to 20 carbon atoms, and R¹ and R² may be the same as ordifferent from each other, but do not represent a hydrogen atomsimultaneously in any case.

R¹ and R² may form a cyclic amino group, together with a nitrogen atomto which R¹ and R² are bonded. Examples of the cyclic amino groupinclude a piperidino group, a morpholino group, a pyrrolidino group, ahexahydroazepino group, and a piperazino group.

R¹ and R² are each independently preferably an alkyl group having 1 to20 carbon atoms, more preferably an alkyl group having 1 to 10 carbonatoms, and still more preferably an alkyl group having 1 to 5 carbonatoms.

R³ and R⁴ each represent an electron-withdrawing group. Here, theelectron-withdrawing group is an electron-withdrawing group having aHammett's substituent constant, a σ_(p) value (hereinafter simplyreferred to as a “σ_(p) value”) from 0.20 to 1.0, and preferably anelectron-withdrawing group having a σ_(p) value from 0.30 to 0.8. R³ andR⁴ may be bonded to each other to form a ring. R³ and R⁴ are eachpreferably an acyl group, a carbamoyl group, an alkyloxycarbonyl group,an aryloxycarbonyl group, a cyano group, a nitro group, an alkylsulfonylgroup, an arylsulfonyl group, a sulfonyloxy group, or a sulfamoyl group,and more preferably an acyl group, a carbamoyl group, analkyloxycarbonyl group, an aryloxycarbonyl group, a cyano group, analkylsulfonyl group, an arylsulfonyl group, a sulfonyloxy group, or asulfamoyl group.

At least one of R¹, R², R³, or R⁴ may be in the form of a polymerderived from a monomer bonded to a vinyl group via a linking group, or acopolymer with other monomers.

Specific examples of the ultraviolet absorber represented by GeneralFormula (UV) include a compound represented by the following formula.With regard to the description of a substituent of the ultravioletabsorber represented by General Formula (UV), reference can be made tothe descriptions in paragraph Nos. 0024 to 0033 of WO2009/123109A(<0040> to <0059> of the corresponding US2011/0039195A), the content ofwhich is incorporated herein by reference. With regard to specificpreferred examples of the compound represented by General Formula (UV),reference can be made to the descriptions of Exemplary Compounds (1) to(14) in paragraph Nos. 0034 to 0037 of WO2009/123109A (<0060> of thecorresponding US2011/0039195A), the content of which is incorporatedherein by reference.

Examples of commercially available products of the ultraviolet absorberinclude UV503 (Daito Chemical Co., Ltd.). In addition, as theultraviolet absorber, ultraviolet absorbers such as an aminodiene-basedcompound, a salicylate-based compound, a benzophenone-based compound, abenzotriazole-based compound, an acrylonitrile-based compound, and atriazine-based compound can be used. Specific examples thereof includethe compounds described in JP2013-68814A. As the benzotriazole-basedcompound, MYUA series manufactured by MIYOSHI OIL & FAT Co., LTD. (TheChemical Daily, Feb. 1, 2016) may also be used.

<Surfactant>

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention may include a surfactant. By incorporation of thesurfactant, it is possible to form a pattern having less adhesivenessand fewer developing defects with good sensitivity and resolution in acase where an exposure light source at a wavelength of 250 nm or less,and particularly 220 nm or less is used.

As the surfactant, fluorine-based and/or silicon-based surfactants areparticularly preferably used.

Examples of the fluorine-based and/or silicon-based surfactants includethe surfactants described in <0276> of US2008/0248425A. Further, EFTOPEF301 or EF303 (manufactured by Shin-Akita Kasei K.K.); FLORAD FC430,431, or 4430 (manufactured by Sumitomo 3M Inc.); MEGAFACE F171, F173,F176, F189, F113, F110, F177, F120, or R08 (manufactured by DICCorporation); SURFLON S-382, SC101, 102, 103, 104, 105, or 106(manufactured by Asahi Glass Co., Ltd.); TROYSOL S-366 (manufactured byTroy Chemical); GF-300 or GF-150 (manufactured by Toagosei ChemicalIndustry Co., Ltd.); SURFLON S-393 (manufactured by Seimi Chemical Co.,Ltd.); EFTOP EF121, EF122A, EF122B, RF122C, EF125M, EF135M, EF351,EF352, EF801, EF802, or EF601 (manufactured by JEMCO Inc.); PF636,PF656, PF6320, or PF6520 (manufactured by OMNOVA); or FTX-204G, 208G,218G, 230G, 204D, 208D, 212D, 218D, or 222D (manufactured by NEOS Co.,Ltd.) may be used. In addition, a polysiloxane polymer KP-341(manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as thesilicon-based surfactant.

Furthermore, in addition to those known surfactants as shown above, thesurfactant may be synthesized using a fluoro-aliphatic compound producedby a telomerization process (also called a telomer process) or anoligomerization process (also called an oligomer process). Specifically,a polymer including a fluoro-aliphatic group derived from thefluoro-aliphatic compound may be used as a surfactant as the surfactant.The fluoro-aliphatic compound can be synthesized in accordance with themethod described in JP2002-90991A.

In addition, the surfactants described in <0280> of US2008/0248425Aother than the fluorine-based and/or silicon-based surfactants may beused.

These surfactants may be used alone or in combination of two or morekinds thereof.

In a case where the actinic ray-sensitive or radiation-sensitivecomposition of the present invention includes a surfactant, the contentof the surfactant is preferably more than 0% by mass and 2% by mass orless, more preferably 0.0001% to 2% by mass, and still more preferably0.0005% to 1% by mass, with respect to the total solid content of theactinic ray-sensitive or radiation-sensitive composition.

<Other Additives>

The actinic ray-sensitive or radiation-sensitive composition of thepresent invention may further include, as such other additives, at leastone selected from a dye, a plasticizer, a photosensitizer, a lightabsorber, and a compound enhancing the solubility in a developer.

[Method for Purifying Actinic Ray-Sensitive or Radiation-SensitiveComposition]

The method for purifying an actinic ray-sensitive or radiation-sensitivecomposition of the present invention includes subjecting a solution ofan actinic ray-sensitive or radiation-sensitive composition containing ametal cation and a ligand to circulation filtration, using a filter of apolyethylene-based resin. The number of particles in liquid havingparticle diameters of 0.15 μm or less included in 1 mL of the actinicray-sensitive or radiation-sensitive composition obtained by the methodfor purifying an actinic ray-sensitive or radiation-sensitivecomposition of the present invention is 10 or less.

<Filter of Polyethylene-Based Resin>

The filter of a polyethylene-based resin is a filter which has apolyethylene-based resin as a filtering material. Since the filter of apolyethylene-based resin has polyethylene-based resin fibers tightlypacked as a filtering material, the size exclusion effect is significantand fine foreign matters can be effectively removed.

The polyethylene-based resin is a homopolymer or copolymer which hasethylene units in the main chain, and specific examples thereof includepolyethylene and high-density polyethylene.

The filter pore diameter of the filter of a polyethylene-based resin ispreferably 50 nm or less, more preferably 30 nm or less, and mostpreferably 10 nm or less. The lower limit value of the filter porediameter is preferably 1 nm or more, and more preferably 2 nm or more.In a case where the pore diameter of the filter is 50 nm or less,foreign matters can be sufficiently removed, while in a case where thepore diameter is 1 nm or more, the filtration velocity is notexcessively lowered.

In the present invention, a filter of a polyamide-based resin can alsobe used in combination with the filter of a polyethylene-based resin.

The filter of a polyamide-based resin is a filter having apolyamide-based resin as a filtering material. Since the filter of apolyamide-based resin has a polyamide-based resin with polarity as afiltering material, foreign matters with high polarity can beeffectively removed.

The polyamide-based resin is a homopolymer or copolymer which has amidebonds in the main chain thereof, and specific examples thereof includePolyamide 6 and Polyamide 66.

The filter pore diameter of the filter of a polyamide-based resin ispreferably 40 nm or less, more preferably 20 nm or less, and mostpreferably 10 nm or less. The lower limit value of the filter porediameter of the filter of a polyamide-based resin is preferably 1 nm ormore, and more preferably 2 nm or more.

In a case where the filter pore diameter of the filter of apolyamide-based resin is 40 nm or less, foreign matters can besufficiently removed, and in a case where the filter pore diameter is 1nm or more, the filtration velocity is not excessively slowed down.

<Filtration Device>

In a case where two or more kinds of filters are used in combination, itis preferable that the 2 two or more kinds of filters are configured tobe connected in series such that a solution of the actinic ray-sensitiveor radiation-sensitive composition passes through the two or more kindsof filters. Any of the filters may be configured to pass first. There isno limit in the number of filters.

Furthermore, in the purification method of the present invention, asolution of the actinic ray-sensitive or radiation-sensitive compositionis subjected to filtration while circulating the solution in afiltration device, and therefore, a filter which further includes a pump(for example, a chemical pump) for supplying a solution of the actinicray-sensitive or radiation-sensitive composition to the filter can besuitably used as the filtration device.

<Circulation Filtration>

In the purification method of the present invention, a solution of theactinic ray-sensitive or radiation-sensitive composition is subjected tofiltration (which filtration may hereinafter be referred to as“circulation filtration” in some cases) while circulating the solutionin a filtration device as described above to pass through a filter inplural times. The number of circulations is 1 or more, preferably 2 to99, more preferably 4 to 49, and still more preferably 9 to 29. Thecirculation makes it easy to remove foreign matters. Incidentally, in acase where the number of circulations is 99 or less, the filtration timeis not longer, and thus the productivity is excellent. The number ofcirculations is a number obtained by subtracting 1 from the number ofpassages of the solution of the actinic ray-sensitive orradiation-sensitive composition through the filter. That is, in a casewhere the solution passes through the filter twice, the number ofcirculations is 1. In a case where the number of passages of the actinicray-sensitive or radiation-sensitive composition through the filter is 2or more, there is no particular limitation, but the number is preferably3 to 100, more preferably 5 to 50, and still more preferably 10 to 30.

For example, in a case where the circulation filtration is performedusing a device as shown in FIG. 1, the number of circulations can becalculated as [(Integrated amount of the solution of the actinicray-sensitive or radiation-sensitive composition passing through thefirst filter)/(Amount of the solution of the actinic ray-sensitive orradiation-sensitive composition introduced into the tank)−1].

In addition, in a case where the circulation filtration is performedusing a device as shown in FIG. 2, the number of circulations can becalculated as [(Integrated amount of the solution of the actinicray-sensitive or radiation-sensitive composition passing through thefirst filter)/(Amount of the solution of the actinic ray-sensitive orradiation-sensitive composition introduced into the tank)−1].

The time taken for the circulation filtration is preferably 1 day orless. In a case where the filtration time is 1 day or less, the solutionof the actinic ray-sensitive or radiation-sensitive composition hardlycauses a chemical change in an environment during the passage throughthe filtration material, and is thus hardly deteriorated.

Other conditions for the circulation filtration are not particularlylimited. However, the velocity (filtration velocity) at which thesolution of the actinic ray-sensitive or radiation-sensitive compositionpasses through the filter is preferably set to 20 to 110 Lm²/hour, andmore preferably 50 to 110 Lm²/hour, in terms of a filtration linevelocity. In a case where the filtration line velocity is 20 Lm²/hour ormore, it is less likely to cause filtration failure due to aninsufficient pressure even in a case where the viscosity of the solutionof the actinic ray-sensitive or radiation-sensitive compositionviscosity is high. On the other hand, in a case where the filtrationline velocity is 110 Lm²/hour or less, the foreign matters adsorbedand/or captured in the filter are hardly released again.

Furthermore, the temperature (filtration temperature) at which thesolution of the actinic ray-sensitive or radiation-sensitive compositionpasses through the filter is preferably set to 15° C. to 30° C., andmore preferably 17° C. to 25° C. from the viewpoint of maintain thequality of the solution of the actinic ray-sensitive orradiation-sensitive composition. In a case where the filtrationtemperature is 15° C. or higher, aggregates in the solution of theactinic ray-sensitive or radiation-sensitive composition are easilygenerated. On the other hand, in a case where the filtration temperatureis 30° C. or lower, the solution of the actinic ray-sensitive orradiation-sensitive composition is hardly deteriorated.

[Pattern Forming Method]

The pattern forming method of the present invention is a pattern formingmethod including the method for purifying an actinic ray-sensitive orradiation-sensitive composition of the present invention.

The pattern forming method of the present invention is preferably apattern forming method further including:

(a) a step of forming an actinic ray-sensitive or radiation-sensitivefilm using the actinic ray-sensitive or radiation-sensitive composition,

(b) a step of exposing the actinic ray-sensitive or radiation-sensitivefilm with actinic rays or radiation, and

(c) a step of developing the exposed actinic ray-sensitive orradiation-sensitive film with a developer, using an actinicray-sensitive or radiation-sensitive composition purified by the methodfor purifying an actinic ray-sensitive or radiation-sensitivecomposition of the present invention.

<Step (a)>

The step (a) is a step of forming an actinic ray-sensitive orradiation-sensitive film using an actinic ray-sensitive orradiation-sensitive composition. The step (a) is preferably a step offorming an actinic ray-sensitive or radiation-sensitive film by applyingan actinic ray-sensitive or radiation-sensitive composition onto asubstrate.

The actinic ray-sensitive or radiation-sensitive composition ispreferably a resist composition, and the actinic ray-sensitive orradiation-sensitive film is preferably a resist film.

Examples of the substrate include the same ones as substrates used inthe production of a precision integrated circuit element, such as, forexample, a silicon wafer, a silica substrate, a substrate includingother inorganic materials, a polymer substrate with an organic polymer(for example, a polycarbonate, a polyimide, a polyester, a polyalkene,and a mixture or copolymer thereof) or the like, and a combinationthereof.

Examples of the application method include suitable application methodssuch as spin coating, roll coating, flow coating, dip coating, spraycoating, and doctor coating. Among those, the spin coating ispreferable, and the rotation speed is preferably 500 to 10,000revolutions per minute (rpm), more preferably 1,000 to 7,500 rpm, andstill more preferably 2,000 to 6,000 rpm. If desired, various base films(an inorganic film, an organic film, or an antireflection film) may alsobe formed on the lower layer of the actinic ray-sensitive orradiation-sensitive film.

The thickness of the actinic ray-sensitive or radiation-sensitive filmis preferably 1 μm or less, more preferably 250 nm or less, still morepreferably 1 to 50 nm, particularly preferably 1 to 40 nm, and mostpreferably 1 to 25 nm.

After forming the actinic ray-sensitive or radiation-sensitive film onthe substrate, the actinic ray-sensitive or radiation-sensitive film maybe heated to remove the solvent included in the film and stabilize thefilm. The heating temperature is preferably 45° C. to 150° C., morepreferably 50° C. to 130° C., and still more preferably 60° C. to 110°C. The heating time is preferably 0.1 minutes or more, more preferably0.5 to 30 minutes, and still more preferably 0.75 to 10 minutes.

<Step (b)>

The step (b) is a step of exposing the actinic ray-sensitive orradiation-sensitive film with actinic rays or radiation, and can beperformed by the following method, for example.

The actinic ray-sensitive or radiation-sensitive film formed as above isirradiated with actinic rays or radiation by passing the film through apredetermined mask. Further, the irradiation with electron beams isgenerally lithography (direct drawing) that is performed not through amask.

The actinic rays or radiation is not particularly limited, but examplesthereof include a KrF excimer laser, an ArF excimer laser, extremeultraviolet rays, and electron beams, from which the extreme ultravioletrays or the electron beams are particularly preferable, and the extremeultraviolet rays are the most preferable.

The exposure dose for radiation is preferably 1 to 150 mJ/cm², morepreferably 2 to 100 mJ/cm², and still more preferably 3 to 50 mJ/cm².

The exposure dose for electron beams is preferably from 0.1 μC/cm² to 5mC/cm², more preferably from 0.5 μC/cm² to 1 mC/cm², and still morepreferably from 1 μC/cm² to 100 μC/cm².

In a case where the actinic ray-sensitive or radiation-sensitivecomposition (A) containing the suboxide cation (a1) of a metal atom, thecounter anion (a2), the peroxide-based ligand (a3), and water (a4) asdescribed above is used as the actinic ray-sensitive orradiation-sensitive composition, the “—O—O—” bond in a complex formedfrom (a1), (a2), and (a3) is broken by the energy of actinic rays orradiation to form a “M-O-M” bond (M represents a metal atom). That is,it is considered that since the compositions in the exposed area and theunexposed area are changed and the solubility in a developer is thuschanged, it is possible to form a pattern.

Furthermore, in a case where the actinic ray-sensitive orradiation-sensitive composition (B) containing the cation (b1) includinga metal atom, the organic ligand (b2), and the organic solvent (b3) asdescribed above is used as the actinic ray-sensitive orradiation-sensitive composition, the “M-C” bond or the “M-O₂C” bond in acomplex formed from (b1) and (b2) is broken by the energy of actinicrays or radiation to form a “M-O” bond or a “M-O—H” bond. That is, it isconsidered that since the compositions in the exposed area and theunexposed area are changed and the solubility in a developer is thuschanged, it is possible to form a pattern.

<Post-Exposure Baking (PEB)>

In the pattern forming method of the present invention, baking (heating)is preferably performed after the exposure and before performing thedevelopment. The heating temperature is not particularly limited as longas a good pattern is formed, and is preferably 45° C. to 150° C., morepreferably 50° C. to 130° C., and still more preferably 60° C. to 110°C. The number of times of performing PEB may be one or plural. Theheating time is preferably 0.1 minutes or more, more preferably 0.5 to30 minutes, and still more preferably 0.75 to 10 minutes. The heatingcan be performed by a means equipped in a normal exposure or developmentmachine, and may also be performed by using a hot plate or the like.

<Step (c)>

The step (c) is a step of developing the exposed actinic ray-sensitiveor radiation-sensitive film with a developer.

<Developer>

The developer is preferably a developer containing an alkali developeror an organic solvent. The developer containing an organic solvent canalso be referred to as an organic developer.

(Alkali Developer)

As the alkali developer, an aqueous alkaline solution of inorganicalkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate,sodium silicate, sodium metasilicate, and aqueous ammonia, primaryamines such as ethylamine and n-propylamine, secondary amines such asdiethylamine and di-n-butylamine, tertiary amines such as triethylamineand methyldiethylamine, alcohol amines such as dimethylethanolamine andtriethanolamine, tetraalkylammonium hydroxides such astetramethylammonium hydroxide, tetraethylammonium hydroxide,tetrapropylammonium hydroxide, tetrabutylammonium hydroxide,tetrapentylammonium hydroxide, tetrahexylammonium hydroxide,tetraoctylammonium hydroxide, ethyltrimethylammonium hydroxide,butyltrimethylammonium hydroxide, methyltriamylammonium hydroxide, anddibutyldipentylammonium hydroxide, quaternary ammonium salts such asdimethylbis(2-hydroxyethyl)ammonium hydroxide, trimethylphenylammoniumhydroxide, trimethylbenzylammonium hydroxide, and triethylbenzylammoniumhydroxide, cyclic amines such as pyrrole and piperidine, or the like canbe used.

Furthermore, alcohols or a surfactant can also be added in anappropriate amount to the aqueous alkaline solution.

The alkali concentration of the alkali developer is usually 0.1% to 20%by mass. The pH of the alkali developer is usually 10.0 to 15.0.

An aqueous solution including 2.38% by mass of tetramethylammoniumhydroxide is particularly preferable as the alkali developer.

Generally, the developer can be an aqueous acid or base. In order toobtain a sharper image, an aqueous base can be generally used. In orderto reduce contaminations caused by the developer, it may be preferablein some cases to use a developer including no metal atom. Accordingly, acomposition of a quaternary ammonium hydroxide such astetramethylammonium hydroxide, tetraethylammonium hydroxide,tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and acombination thereof is preferable as the developer. A particularlypreferred quaternary ammonium hydroxide can be represented by R₄NOH (inwhich R is a methyl group, an ethyl group, a propyl group, a butylgroup, or a combination thereof). Further, a mixed quaternarytetraalkylammonium hydroxide can be selected based on empiricalevaluation in order to obtain an improved line edge contour. The contentratio of tetraalkylammonium hydroxide in the developer is preferablyabout 2% to about 40% by mass, more preferably about 3% to about 35% bymass, and still more preferably about 4% to about 30% by mass.

The developer may include additives to facilitate the developing step,in addition to the components. Suitable examples of the additivesinclude a dissolved salt having a cation selected from the groupconsisting of ammonium, a d-block metal cation (hafnium, zirconium, andthe like), a f-block metal cation (lanthanum, cerium, lutetium, and thelike), a p-block metal cation (aluminum, tin, and the like), an alkalimetal (lithium, sodium, potassium, and the like), and a combinationthereof, and a dissolved salt having an anion selected from the groupconsisting of fluorine, chlorine, bromine, iodine, nitric acid, sulfuricacid, phosphoric acid, silicic acid, boric acid, peroxide, butoxide,formic acid, ethylenediamine-tetraacetic acid (EDTA), tungstic acid,molybdenum acid, and the like, and a combination thereof. In a casewhere these optionally selected additives exist, the developerpreferably includes about 10% by mass or less of the additives, and morepreferably includes about 5% by mass or less of the additives. Theseadditives can be selected so as to improve contrast, sensitivity, andline width roughness. In addition, by incorporating the additives intothe developer, it is possible to suppress formation and precipitation ofHfO₂/ZrO₂ particles.

(Organic Developer)

Next, the organic solvent included in the organic developer will bedescribed.

The vapor pressure of the organic solvent (or an overall vapor pressurethereof in a case of a mixed solvent) at 20° C. is preferably 5 kPa orless, more preferably 3 kPa or less, and still more preferably 2 kPa orless. By setting the vapor pressure of the organic solvent to 5 kPa orless, evaporation of the developer on a substrate or in a developmentcup is suppressed, the temperature uniformity in the wafer plane isimproved, and as a result, the dimensional uniformity in the wafer planeis improved.

Various organic solvents are widely used as the organic solvent for usein the organic developer, but for example, solvents such as anester-based solvent, a ketone-based solvent, an alcohol-based solvent,an amide-based solvent, an ether-based solvent, and a hydrocarbon-basedsolvent can be used.

The ester-based solvent is a solvent having an ester bond in themolecule, the ketone-based solvent is a solvent having a ketone group inthe molecule, the alcohol-based solvent is a solvent having an alcoholichydroxyl group in the molecule, the amide-based solvent is a solventhaving an amide group in the molecule, and the ether-based solvent is asolvent having an ether bond in the molecule. Among these, there is alsoa solvent having a plurality of the functional groups in one molecule,but in this case, such a solvent shall correspond to any solvent typeincluding the functional group possessed by the solvent. For example, itis assumed that diethylene glycol monomethyl ether shall also fall underany of an alcohol-based solvent and an ether-based solvent in thecategories. In addition, the hydrocarbon-based solvent is a hydrocarbonsolvent having no substituent.

In particular, an organic developer containing at least one solventselected from an ester-based solvent, a ketone-based solvent, anether-based solvent, and a hydrocarbon-based solvent is preferable, anorganic developer containing an ester-based solvent is more preferable,an organic developer containing butyl acetate or isoamyl acetate isstill more preferable, and an organic developer containing isoamylacetate is the most preferable.

Examples of the ester-based solvent include methyl acetate, ethylacetate, butyl acetate, isobutyl acetate, pentyl acetate, propylacetate, isopropyl acetate, amyl acetate (pentyl acetate), isoamylacetate (isopentyl acetate, 3-methylbutyl acetate), 2-methylbutylacetate, 1-methylbutyl acetate, hexyl acetate, heptyl acetate, octylacetate, ethyl methoxyacetate, ethyl ethoxyacetate, butyl butyrate,methyl 2-hydroxyisobutyrate, propylene glycol monomethyl ether acetate(PGMEA; also referred to as 1-methoxy-2-acetoxypropane), ethylene glycolmonoethyl ether acetate, ethylene glycol monopropyl ether acetate,ethylene glycol monobutyl ether acetate, ethylene glycol monophenylether acetate, diethylene glycol monomethyl ether acetate, diethyleneglycol monopropyl ether acetate, diethylene glycol monoethyl etheracetate, diethylene glycol monophenyl ether acetate, diethylene glycolmonobutyl ether acetate, diethylene glycol monoethyl ether acetate,2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate,3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate,propylene glycol monoethyl ether acetate, propylene glycol monopropylether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate,4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentylacetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate,3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate,4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methylformate, ethyl formate, butyl formate, propyl formate, ethyl lactate,butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butylcarbonate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, butylpyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate,ethyl propionate, propyl propionate, isopropyl propionate, butylpropionate, pentyl propionate, hexyl propionate, heptyl propionate,butyl butanoate, isobutyl butanoate, pentyl butanoate, hexyl butanoate,isobutyl isobutanoate, propyl pentanoate, isopropyl pentanoate, butylpentanoate, pentyl pentanoate, ethyl hexanoate, propyl hexanoate, butylhexanoate, isobutyl hexanoate, methyl heptanoate, ethyl heptanoate,propyl heptanoate, cyclohexyl acetate, cycloheptyl acetate, 2-ethylhexylacetate, cyclopentylpropionate, methyl 2-hydroxypropionate, ethyl2-hydroxypropionate, methyl-3-methoxypropionate,ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, andpropyl-3-methoxypropionate. Among these, butyl acetate, amyl acetate,isoamyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexylacetate, pentyl propionate, hexyl propionate, heptyl propionate, orbutyl butanoate is preferably used, and butyl acetate or isoamyl acetateis particularly preferably used.

Examples of the ketone-based solvent include 1-octanone, 2-octanone,1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone,2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone,phenyl acetone, methyl ethyl ketone, methyl isobutyl ketone,acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, propylenecarbonate, and γ-butyrolactone, and among these, 2-heptanone ispreferable.

Examples of the alcohol-based solvents include alcohols (monovalentalcohols) such as methanol, ethanol, 1-propanol, isopropanol, 1-butanol,2-butanol, 3-methyl-1-butanol, tert-butyl alcohol, 1-pentanol,2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 1-decanol, 2-hexanol,2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol,3-methyl-3-pentanol, cyclopentanol, 2,3-dimethyl-2-butanol,3,3-dimethyl-2-butanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol,3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-2-pentanol(methylisobutyl carbinol), 4-methyl-3-pentanol, cyclohexanol,5-methyl-2-hexanol, 4-methyl-2-hexanol, 4,5-dimethyl-2-hexanol,6-methyl-2-heptanol, 7-methyl-2-octanol, 8-methyl-2-nonanol,9-methyl-2-decanol, and 3-methoxy-1-butanol, glycol-based solvents suchas ethylene glycol, diethylene glycol, and triethylene glycol, andhydroxyl group-containing glycol ether-based solvents such as ethyleneglycol monomethyl ether, propylene glycol monomethyl ether (PGME; alsoreferred to as 1-methoxy-2-propanol), diethylene glycol monomethylether, triethylene glycol monoethyl ether, methoxymethylbutanol,ethylene glycol monoethyl ether, ethylene glycol monopropyl ether,ethylene glycol monobutyl ether, propylene glycol monoethyl ether,propylene glycol monopropyl ether, propylene glycol monobutyl ether, andpropylene glycol monophenyl ether. Among these, the glycol ether-basedsolvent is preferably used.

Examples of the ether-based solvent include glycol ether-based solventshaving no hydroxyl group, such as propylene glycol dimethyl ether,propylene glycol diethyl ether, dipropylene glycol dimethyl ether,dipropylene glycol diethyl ether, diethylene glycol dimethyl ether, anddiethylene glycol diethyl ether, aromatic ether solvents such as anisoleand phenetole, dioxane, tetrahydrofuran, tetrahydropyran,perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, and1,4-dioxane, in addition to the glycol ether-based solvents containing ahydroxyl group. Other examples thereof include a cyclic aliphaticether-based solvent having a branched alkyl group, such ascyclopentylisopropyl ether, cyclopentyl sec-butyl ether, cyclopentyltert-butyl ether, cyclohexylisopropyl ether, cyclohexyl sec-butyl ether,and cyclohexyl tert-butyl ether, an acyclic aliphatic ether-basedsolvent having a linear alkyl group, such as di-n-propyl ether,di-n-butyl ether, di-n-pentyl ether, and di-n-hexyl ether, and anacyclic aliphatic ether-based solvent having a branched alkyl group,such as diisohexyl ether, methylisopentyl ether, ethylisopentyl ether,propylisopentyl ether, diisopentyl ether, methylisobutyl ether,ethylisobutyl ether, propylisobutyl ether, diisobutyl ether, diisopropylether, ethylisopropyl ether, and methylisopropyl ether. Among those,from the viewpoint of uniformity in the wafer plane, an acyclicaliphatic ether-based solvent having 8 to 12 carbon atoms is preferable,an acyclic aliphatic ether-based solvent having a branched alkyl grouphaving 8 to 12 carbon atoms is more preferable, and diisobutyl ether,diisopentyl ether, or diisohexyl ether is particularly preferable.

As the amide-based solvent, for example, N-methyl-2-pyrrolidone,N,N-dimethylacetamide, N,N-dimethylformamide, hexamethylphosphorictriamide, and 1,3-dimethyl-2-imidazolidinone can be used.

Examples of the hydrocarbon-based solvent include aliphatichydrocarbon-based solvents such as pentane, hexane, octane, nonane,decane, dodecane, undecane, hexadecane, 2,2,4-trimethylpentane,2,2,3-trimethylhexane, perfluorohexane, and perfluoroheptane, aromatichydrocarbon-based solvents such as toluene, xylene, ethylbenzene,propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene,dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene,ethyldimethylbenzene, and dipropylbenzene, and unsaturatedhydrocarbon-based solvents such as octene, nonene, decene, undecene,dodecene, and hexadecene.

The double bond and the triple bond contained in the unsaturatedhydrocarbon-based solvent may be in plural numbers, and may be presentat any position of the hydrocarbon chain. Cis and trans forms of theunsaturated hydrocarbon-based solvents may be present as a mixture dueto incorporation of double bonds.

Incidentally, the hydrocarbon-based solvent may be a mixture ofcompounds having the same number of carbon atoms and a differentstructure. For example, in a case where decane is used as the aliphatichydrocarbon-based solvent, 2-methylnonane, 2,2-dimethyloctane,4-ethyloctane, isodecane, and the like, which are compounds having thesame number of carbon atoms and a different structure, may be includedin the aliphatic hydrocarbon-based solvent.

Moreover, the compounds having the same number of carbon atoms anddifferent structures may be included singly or may be included as aplurality of kinds thereof as described above.

In a case where extreme ultraviolet rays or electron beams are used inthe exposing step, for the organic solvent included in the organicdeveloper, an ester-based solvent having 7 or more carbon atoms(preferably 7 to 14 carbon atoms, more preferably 7 to 12 carbon atoms,and still more preferably 7 to 10 carbon atoms) and 2 or lessheteroatoms is preferably used in a view of suppressing the swelling ofthe actinic ray-sensitive or radiation-sensitive film.

The heteroatom of the ester-based solvent is an atom other than a carbonatom and a hydrogen atom, and examples thereof include an oxygen atom, anitrogen atom, and a sulfur atom. The number of heteroatoms ispreferably 2 or less.

Preferred examples of the ester-based solvent having 7 or more carbonatoms and having 2 or less heteroatoms include amyl acetate, isoamylacetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate,pentyl propionate, hexyl propionate, butyl propionate, isobutylisobutyrate, heptyl propionate, and butyl butanoate, and isoamyl acetateis particularly preferable.

In a case where extreme ultraviolet rays or electron beams are used inthe exposing step, the organic solvent included in the organic developermay be a mixed solvent of the ester-based solvent and thehydrocarbon-based solvent or a mixed solvent of the ketone-based solventand the hydrocarbon-based solvent in place of the ester-based solventhaving 7 or more carbon atoms and having 2 or less heteroatoms. Also inthis case, it is effective in suppressing the swelling of the actinicray-sensitive or radiation-sensitive film.

In a case where an ester-based solvent and a hydrocarbon-based solventare used in combination, it is preferable to use isoamyl acetate as theester-based solvent. From the viewpoint of adjusting the solubility ofthe actinic ray-sensitive or radiation-sensitive film, a saturatedhydrocarbon solvent (for example, octane, nonane, decane, dodecane,undecane, and hexadecane) is preferably used as the hydrocarbon-basedsolvent.

In a case where a ketone-based solvent and a hydrocarbon-based solventare used in combination, it is preferable to use 2-heptanone as theketone-based solvent. From the viewpoint of adjusting the solubility ofan actinic ray-sensitive or radiation-sensitive film, a saturatedhydrocarbon solvent (for example, octane, nonane, decane, dodecane,undecane, and hexadecane) is preferably used as the hydrocarbon-basedsolvent.

In a case where the mixed solvent is used, the content of thehydrocarbon-based solvent depends on solvent solubility of an actinicray-sensitive or radiation-sensitive film and is not particularlylimited. Therefore, the necessary amount of the hydrocarbon-basedsolvent may be determined by appropriately adjusting such a mixedsolvent.

The organic solvent may be used as a mixture of a plurality of solventsor may be used in admixture with a solvent other than those describedabove or with water. However, it is preferable that the moisture contentof the whole developer is less than 10% by mass, and it is morepreferable that the developer is substantially free of water. Theconcentration of the organic solvent (total concentration of solvents ina case of mixing a plurality of solvents) in the developer is preferably50% by mass or more, more preferably 50% to 100% by mass, still morepreferably 85% to 100% by mass, even still more preferably 90% to 100%by mass, and particularly preferably 95% to 100% by mass. Most preferredis a case consisting of substantially only an organic solvent. The caseconsisting of substantially only an organic solvent is intended toinclude a case containing a trace amount of a surfactant, anantioxidant, a stabilizer, an anti-foaming agent, or the like.

It is also preferable that the developer contains an antioxidant so thatthe generation of an oxidant over time can be suppressed and the contentof the oxidant can be further reduced. A known antioxidant may be usedas the antioxidant. In a case where the antioxidant is used forsemiconductor applications, an amine-based antioxidant or a phenol-basedantioxidant is preferably used.

The content of the antioxidant is not particularly limited, but it ispreferably 0.0001% to 1% by mass, more preferably 0.0001% to 0.1% bymass, and still more preferably 0.0001% to 0.01% by mass, with respectto the total mass of the developer. In a case where the content of theantioxidant is 0.0001% by mass or more, a superior antioxidant effect isobtained. In a case where the content of the antioxidant is 1% by massor less, there is tendency that generation of development residues canbe suppressed.

The developer may contain a basic compound.

The developer may contain a surfactant. By incorporating the surfactantinto the developer, the wettability for the actinic ray-sensitive orradiation-sensitive film is improved, and thus, the development proceedsmore effectively.

In a case where the developer contains a surfactant, the content of thesurfactant is preferably 0.001% to 5% by mass, more preferably 0.005% to2% by mass, and still more preferably 0.01% to 0.5% by mass, withrespect to the total mass of the developer.

As the developing method, for example, a method in which a substrate isimmersed in a tank filled with a developer for a certain period of time(a dip method), a method in which development is performed by heaping adeveloper up onto the surface of a substrate by surface tension, andthen allowing to stand it for a certain period of time (a puddlemethod), a method in which a developer is sprayed on the surface of asubstrate (a spray method), a method in which a developer iscontinuously discharged onto a substrate spun at a constant rate whilescanning a developer discharging nozzle at a constant rate (a dynamicdispense method), or the like can be applied.

Moreover, after the step of performing development, a step of stoppingthe development by replacing the solvent with another solvent may becarried out.

The development time is not particularly limited, but is usually 10 to300 seconds, and preferably 20 to 120 seconds.

The temperature of the developer is preferably 0° C. to 50° C., and morepreferably 15° C. to 35° C.

In the developing step, both of development using a developer containingan organic solvent and development using an alkali developer may beperformed (so-called double development).

<Step (d)>

The pattern forming method of the present invention preferably has astep (d) of rising (washing) the developed actinic ray-sensitive orradiation-sensitive film after the step (c) using a rinsing liquid.

<Rinsing Liquid>

As the rinsing liquid in the rinsing treatment which is performed afterthe alkali development, pure water is used, or an appropriate amount ofa surfactant can also be added thereto and the mixture can be used.

In addition, after the developing treatment or the rinsing treatment, atreatment for removing the developer or rinsing liquid adhering on thepattern by a supercritical fluid can be performed.

As the rinsing liquid in the rinsing treatment which is performed afterthe organic solvent development, a rinsing liquid containing an organicsolvent (organic rinsing liquid) is preferably used.

The vapor pressure of the rinsing liquid (overall vapor pressure ofsolvents in a case of being a mixed solvent) at 20° C. is preferablyfrom 0.05 kPa to 5 kPa, more preferably from 0.1 kPa to 5 kPa, and stillmore preferably from 0.12 kPa to 3 kPa. By setting the vapor pressure ofthe rinsing liquid to from 0.05 kPa to 5 kPa, the temperature uniformityin the wafer plane is improved, the swelling due to permeation of therinsing liquid is further suppressed, and the dimensional uniformity inthe wafer plane is improved.

(Organic Solvent)

Various organic solvents are used as the organic solvent included in theorganic rinsing liquid, but it is preferable to use at least one organicsolvent selected from the group consisting of a hydrocarbon-basedsolvent, a ketone-based solvent, an ester-based solvent, analcohol-based solvent, an amide-based solvent, and an ether-basedsolvent. It is particularly preferable that the rinsing liquid includesa hydrocarbon-based solvent. Specific examples of these organic solventsare the same as those of the organic solvents described for thedeveloper.

With regard to the organic solvent included in the organic rinsingliquid, in a case where extreme ultraviolet rays or electron beams areused in the exposure step, it is preferable to use a hydrocarbon-basedsolvent among the organic solvents, and it is more preferable to use analiphatic hydrocarbon-based solvent. From the viewpoint that the effectis more improved, the aliphatic hydrocarbon-based solvent used in therinsing liquid is preferably an aliphatic hydrocarbon-based solventhaving 5 or more carbon atoms (for example, pentane, hexane, octane,decane, undecane, dodecane, and hexadecane), more preferably analiphatic hydrocarbon-based solvent having 8 or more carbon atoms, andstill more preferably an aliphatic hydrocarbon-based solvent having 10or more carbon atoms.

Furthermore, the upper limit of the number of carbon atoms in thealiphatic hydrocarbon-based solvent is not particularly limited, but itmay be, for example, 16 or less, preferably 14 or less, and morepreferably 12 or less.

Among the aliphatic hydrocarbon-based solvents, decane, undecane, ordodecane is particularly preferable, and undecane is most preferable.

By using a hydrocarbon-based solvent (particularly an aliphatichydrocarbon-based solvent) as the organic solvent included in therinsing liquid as above, the developer which has been slightlyimpregnated into the actinic ray-sensitive or radiation-sensitive filmafter the development is washed away to further exert the effects offurther suppressing the swelling and suppressing the pattern collapse.

Furthermore, examples of the hydrocarbon-based solvent also includeunsaturated hydrocarbon-based solvents such as octene, nonene, decene,undecene, dodecene, and hexadecene.

The double bond and the triple bond contained in the unsaturatedhydrocarbon solvent may be plural, and may be present at any position ofthe hydrocarbon chain. Cis and trans forms of the unsaturatedhydrocarbon solvents may be present as a mixture due to incorporation ofdouble bonds.

Moreover, the hydrocarbon-based solvent may be a mixture of compoundshaving the same number of carbon atoms and a different structure. Forexample, in a case where decane is used as the aliphatichydrocarbon-based solvent, 2-methylnonane, 2,2-dimethyloctane,4-ethyloctane, isodecane, and the like, which are compounds having thesame number of carbon atoms and a different structure, may be includedin the aliphatic hydrocarbon-based solvent.

Incidentally, the compounds having the same number of carbon atoms anddifferent structures may be included singly or may be included as aplurality of kinds thereof as described above.

A plurality of organic solvents may be mixed, or may be mixed with anorganic solvent other than those described above. The solvent may bemixed with water, but the moisture content in the rinsing liquid isusually 60% by mass or less, preferably 30% by mass or less, still morepreferably 10% by mass or less, and most preferably 5% by mass or less.By setting the moisture content to 60% by mass or less, good rinsingcharacteristics can be obtained.

The rinsing liquid preferably contains a surfactant. With thesurfactant, the wettability to the actinic ray-sensitive orradiation-sensitive film is improved, and the washing effects tend to befurther improved.

The content of the surfactant is usually 0.001% to 5% by mass,preferably 0.005% to 2% by mass, and still more preferably 0.01% to 0.5%by mass, with respect to the total mass of the rinsing liquid.

The rinsing liquid preferably contains an antioxidant. With theantioxidant, generation of an oxidant over time can be suppressed, andthe content of the oxidant can be further reduced. Specific examples andthe content of the antioxidant are as described in the section ofDeveloper.

In the rinsing step, the wafer subjected to development is subjected towashing using the rinsing liquid. A method for the washing treatment isnot particularly limited, and examples thereof include a method ofcontinuously ejecting a rinsing liquid on a substrate spinning at agiven speed (spin coating method), a method of immersing a substrate ina bath filled with a rinsing liquid for a given period of time (dipmethod), or a method of spraying a rinsing liquid on a substrate surface(spray method). Among them, it is preferable that the washing treatmentis carried out by the spin coating method and then the substrate is spunat a rotation speed of 2,000 rpm to 4,000 rpm to remove the rinsingliquid from the substrate.

<Housing Container>

In a case where the developer is an organic solvent, as an organicsolvent that can be used in the developer and the rinsing liquid, it ispreferable to use one stored in a housing container for housing anorganic treatment liquid, in which the container has a housing portion.The housing container is preferably, for example, a housing containerfor housing an organic treatment liquid, in which the inner wall of thehousing portion being in contact with the organic treatment liquid isformed of a resin different from a polyethylene resin, a polypropyleneresin, and a polyethylene-polypropylene resin, or of a metal that hasbeen subjected to rust-preventing and metal elution-preventingtreatments. An organic solvent to be used as an organic treatment liquidis contained in the housing portion of the housing container, and theorganic solvent discharged from the housing portion can be used in thepattern forming method of the present invention.

In a case where the housing container further has a sealing part forsealing the housing portion, the sealing part is also preferably formedof a resin different from a polyethylene resin, a polypropylene resin,and a polyethylene-polypropylene resin, or of a metal that has beensubjected to rust-preventing and metal elution-preventing treatments.

Here, the sealing part means a member capable of shielding the housingportion from the outside air, and suitable examples thereof include apacking and an O ring.

The resin different from a polyethylene resin, a polypropylene resin,and a polyethylene-polypropylene resin is preferably a perfluoro resin.

Examples of the perfluoro resin include a tetrafluoroethylene resin(PTFE), a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin(PFA), a tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP),a tetrafluoroethylene-ethylene copolymer resin (ETFE), atrifluoroethylene chloride-ethylene copolymer resin (ECTFE), apolyvinylidene fluoride resin (PVDF), a trifluoroethylene chloridecopolymer resin (PCTFE), and a polyvinyl fluoride resin (PVF).

Particularly preferred examples of the perfluoro resin include atetrafluoroethylene resin, a tetrafluoroethylene-perfluoroalkyl vinylether copolymer resin, and a tetrafluoroethylene-hexafluoropropylenecopolymer resin.

Examples of the metal which is subjected to the rust-preventing andmetal elution-preventing treatments include carbon steel, alloy steel,nickel chrome steel, nickel chrome molybdenum steel, chrome steel,chrome molybdenum steel, and manganese steel.

As the rust-preventing and metal elution-preventing treatment, a coatingtechnique is preferably applied.

The coating technique is largely divided into three kinds of coatingssuch as metal coating (various platings), inorganic coating (variouschemical conversion treatments, glass, concrete, ceramics, and the like)and organic coating (a rust-preventing oil, a paint, rubber, andplastics).

Preferred examples of the coating technique include a surface treatmentusing a rust-preventing oil, a rust inhibitor, a corrosion inhibitor, achelate compound, a peelable plastic, or a lining agent.

Among those, a surface treatment with various corrosion inhibitors suchas chromate, nitrite, silicate, phosphate, carboxylic acids such asoleic acid, dimer acid, and naphthalenic acid, a carboxylic acidmetallic soap, sulfonate, an amine salt, esters (a glycerin ester or aphosphate ester of a higher fatty acid), and chelate compounds such asethylenediaminetetraacetic acid, gluconic acid, nitrilotriacetic acid,hydroxyethylethylenediaminetriacetic acid, anddiethylenetriaminepentaacetic acid, and a lining with a fluorine resinare preferable. The surface treatment with a phosphate-treated corrosioninhibitor and the lining with a fluorine resin are particularlypreferable.

Furthermore, a “pre-treatment” which is at a pre-stage for therust-preventing treatment is also preferably employed as a treatmentmethod which leads to extension of an anti-rust period through a coatingtreatment although not directly preventing rust, as compared with adirect coating treatment.

Specific suitable examples of such a pre-treatment include a treatmentfor removing various corrosive factors, such as chloride and sulfate,which are present on a metal surface, through washing or polishing.

Specific examples of the housing container include the following ones.

-   -   FluoroPurePFA complex drum manufactured by Entegris Inc. (liquid        contact inner surface: PFA resin lining)    -   Steel-made drum can be manufactured by JFE (liquid contact inner        surface: zinc phosphate film)

Moreover, examples of the housing container which can be used in thepresent invention include the containers described in <0013> to <0030>of JP1999-021393A (JP-H11-021393A), and <0012> to <0024> ofJP1998-45961A (JP-H10-45961A).

An electrically conductive compound may be added to the organictreatment liquid in the present invention in order to prevent thefailure of chemical liquid pipes or various parts (a filter, an O-ring,a tube, and the like) associated with electrostatic charge andsubsequently occurring electrostatic discharge. The electricallyconductive compound is not particularly limited, but examples thereofinclude methanol. The addition amount thereof is not particularlylimited, but is preferably 10% by mass or less, and more preferably 5%by mass or less, from the viewpoint of maintaining preferred developmentcharacteristics. For the members of the chemical liquid pipes, variouspipes coated with stainless steel (SUS), or with polyethylene,polypropylene, or fluorine resins (polytetrafluoroethylene, aperfluoroalkoxy resin, and the like) which has been subjected to anantistatic treatment can be used. Similarly, with respect to the filtersand the O-rings, polyethylene, polypropylene, or fluorine resins(polytetrafluoroethylene, a perfluoroalkoxy resin, and the like) whichhas been subjected to an antistatic treatment can be used.

Generally, the pattern obtained by the pattern forming method of thepresent invention is suitably used as an etching mask of a semiconductordevice or the like, but it can also be used for other applications.Other applications include, for example, formation of a guide pattern inDirected Self-Assembly (DSA) (see, for example, ACS Nano Vol. 4 No. 8Pages 4815-4823), and use as a core material (core) of a so-calledspacer process (see, for example, JP1991-270227A (JP-H03-270227A) andJP2013-164509A).

[Method for Manufacturing Electronic Device]

The present invention also relates to a method for manufacturing anelectronic device, including the pattern forming method of the presentinvention as described above.

An electronic device manufactured by the method for manufacturing anelectronic device of the present invention is suitably mounted onelectric electronic equipment (such as home electronics, officeautomation (OA) equipment, media-related equipment, optical equipment,telecommunication equipment, and the like).

EXAMPLES

Hereinbelow, the present invention will be described in more detail withreference to Examples, but the present invention is not limited thereto.

Example 1

(Preparation of Actinic Ray-Sensitive or Radiation-Sensitive CompositionContaining Metal Suboxide Cation, Counter Anion, Peroxide-Based Ligand,and Water)

Each of different aqueous solutions for a metal suboxide cation, acounter anion, and a peroxide-based ligand was prepared. The aqueoussolution including the metal suboxide cation is referred to as asolution (A), the aqueous solution including the peroxide-based ligandis referred to as a solution (B), and the aqueous solution including thecounter anion is referred to as a solution (C).

500 mL of ultrapure water (electrical resistivity of 18 MΩ·cm) and 0.5molar ZrOCl₂.8H₂O (99.9% by mass of Alfa Aesar) were mixed to prepare asolution (A). H₂O₂ (aqueous) (30% by mass, Mallinckrodt Baker) wasdiluted with ultrapure water to produce a 6%- to 8%-by-mass H₂O₂(aqueous) solution, thereby preparing a solution (B).

A solution (C) including 2 to 5 mol/L H₂SO₄ (aqueous) was obtained at aguaranteed concentration (Fischer Scientific, 5 mol/L) or aconcentration solution (98% by mass H₂SO₄, Mallinckrodt Baker) thereofwas diluted with ultrapure water.

The solution (A), the solution (B), and the solution (C) wererespectively weighed and put into individual pre-cleaned polyethylenebottles. Ultrapure water in an amount sufficient to obtain a targetedfinal metal concentration was added to the solution (C). 4.8 mL of thesolution (A) (Zr) was poured into 1.8 mL of the solution (B) (H₂O₂) tomix the components in the bottles and left to stand for 5 minutes, andthen 2.16 mL of the solution (C) (H₂SO₄ (aqueous)) and 21.24 mL ofultrapure water were poured into the mixture of the solution (A) and thesolution (B) and further left to stand for 5 minutes.

According to the method, 30 mL of a blend of the solutions having azirconium concentration of 0.16 mol/L was obtained.

The obtained solution was filtered by the method shown in Table 1 whichwill be described later to obtain an actinic ray-sensitive orradiation-sensitive composition (resist composition).

As the filter used in Examples, filters described below were used, but afilter that is usable in the production method of the present inventionis not limited thereto.

For a polyethylene-made filter, “PE-Clean, High-Density Polyethylene(HDPE)” manufactured by Nihon Pall Ltd. was used. As the pore diameter,a pore diameter described in Table 1 was used. The pore diameter isspecifically 2 nm, 5 nm, 10 nm, 30 nm, or 50 nm, and the filteredsurface area is each 1.3 m², 1.3 m², 1.3 m², 1.1 m², or 1.4 m².

As the Nylon 6,6-made filter, “PhotoClean DDF, Ultipleat⋅P-nylon,filtered surface area of 2,500 cm²” manufactured by Nihon Pall Ltd. wasused. The pore diameters described in Table 1 were used.

(Pattern Formation)

An 8-inch silicon wafer was used as a substrate. The surface of thesilicon wafer was pre-treated with a basic surfactant, an acidicsurfactant, O₂ plasma, UV ozone, a piranha etching solution, or dimethylsulfoxide (DMSO). Subsequently, the silicon wafer was heated to 225° C.,and thus, a surface thereof was hydrophilized. The wafer was loaded ontoa spin coater, and the actinic ray-sensitive or radiation-sensitivecomposition was quantitatively discharged in the center of the wafer.The amount of the actinic ray-sensitive or radiation-sensitivecomposition quantitatively discharged was selected based on a desiredcoating thickness and a desired size of the wafer. The spin coater wasrotated at 100 rotations per minute (rpm) for 5 seconds, and the actinicray-sensitive or radiation-sensitive composition was sprayed on theentire wafer, and then rotated at 3,000 rpm for 30 seconds to form anactinic ray-sensitive or radiation-sensitive film (resist film). Thewafer having the actinic ray-sensitive or radiation-sensitive filmformed thereon was pre-exposure baked at 100° C. for 0.1 minutes,thereby forming an actinic ray-sensitive or radiation-sensitive filmhaving a thickness of 50 nm.

The actinic ray-sensitive or radiation-sensitive film was irradiatedwith light rays at a wavelength of 13.5 nm through a pattern mask, usinga lithographic processing system having an EUV laser source (METmanufactured by Exitech Ltd., NA 0.3). After irradiation, the actinicray-sensitive or radiation-sensitive film was post-exposure baked on ahot plate at 100° C. for 1 minute. Using a puddle development method,the actinic ray-sensitive or radiation-sensitive film was developed witha 2.38%-by-mass aqueous tetramethylammonium hydroxide (TMAH) solution.Specifically, the developer was brought into contact with the actinicray-sensitive or radiation-sensitive film for 20 seconds, and then thepattern after development was rinsed with water and dried.

One inch is 25.4 mm.

As a pattern mask to be used, a mask in which a light-shielding bandthat suppresses unnecessary reflection of EUV was disposed in the outercircumference of the pattern may be used, or a mask in which fineirregularities were provided in the bottom of a dug in thelight-shielding band may be used. By using such a mask, it is possibleto form a circuit pattern by suppressing the “out-of-band light”.

Examples 2 to 4

A pattern was obtained by the same method as in Example 1 except thatthe filtration method was changed to a method described in Table 1.

Example 5

(Preparation of Actinic Ray-Sensitive or Radiation-Sensitive CompositionContaining Metal Suboxide Cation, Counter Anion, Peroxide-Based Ligand,and Water)

Each of different aqueous solutions for a metal suboxide cation, acounter anion, and a peroxide-based ligand was prepared. The aqueoussolution including the metal suboxide cation is referred to as asolution (A2), the aqueous solution including the peroxide-based ligandis referred to as a solution (B2), and the aqueous solution includingthe counter anion is referred to as a solution (C2).

A 0.5 molar HfOCl₂.8H₂O (204.76 g, 98% by mass of Alfa Aesar) solutionwhich had been mixed with 500 mL of ultrapure water was filtered toprepare a solution (A2).

H₂O₂ (aqueous) (30% by mass, ultrapure water to produce a 6%- to8%-by-mass Mallinckrodt Baker) was diluted with a (aqueous) H₂O₂solution to prepare a solution (B2).

A solution (C2) including 2 to 5 mol/L H₂SO₄ (aqueous) was obtained at aguaranteed concentration (Fischer Scientific, 5 mol/L) or aconcentration solution (98% by mass H₂SO₄, Mallinckrodt Baker) thereofwas diluted with ultrapure water.

The solution (A2), the solution (B2), and the solution (C2) wererespectively weighed and put into individual pre-cleaned polyethylenebottles. Ultrapure water in an amount sufficient to obtain a targetedfinal metal concentration was added to the solution (C2). Then, 4.5 mLof the solution (A2) (Hf) was poured into 16.875 mL of the solution (B2)(H₂O₂) to mix the components in the bottles and left to stand for 5minutes, and then 1.8 mL of the solution (C2) (H₂SO₄ (aqueous)) and6.825 mL of ultrapure water were poured into the mixture of the solution(A2) and the solution (B2) and further left to stand for 5 minutes.

According to the method, 30 mL of a blend of the solutions having ahafnium concentration of 0.15 mol/L was obtained.

The obtained solution was filtered by the method shown in Table 1 whichwill be described later to obtain an actinic ray-sensitive orradiation-sensitive composition (resist composition).

(Pattern Formation)

A pattern was formed by performing the same procedure as in Example 1using the actinic ray-sensitive or radiation-sensitive compositionobtained above.

Examples 6 to 8

A pattern was obtained by the same method as in Example 5 except thatthe filtration method was changed to a method described in Table 1.

Example 9

(Preparation of Actinic Ray-Sensitive or Radiation-Sensitive CompositionContaining Cation Including Metal Atom, Organic Ligand, and OrganicSolvent)

Powder (TCI America) of 0.209 g of monobutyltin oxide (BuSnOOH) wasadded to 10 mL of 4-methyl-2-pentanol. This solution was placed in anairtight container and stirred for 24 hours. Thereafter, the solutionwas centrifuged for 15 minutes at 4,000 rpm, and the insolubles werefiltered through a polytetrafluoroethylene (PTFE)-made syringe filterhaving a pore diameter of 0.45 μm to obtain an actinic ray-sensitive orradiation-sensitive composition (resist composition).

(Pattern Formation)

A 25 mm×25 mm silicon wafer was used as a substrate. The surface of thesilicon wafer was pretreated with ultraviolet ozone for a 10-minutecycle. A selected actinic ray-sensitive or radiation-sensitivecomposition was spin-coated on the wafer for 30 seconds at 4,500 rpm toform an actinic ray-sensitive or radiation-sensitive film (resist film).The wafer having the actinic ray-sensitive or radiation-sensitive filmformed thereon was pre-exposure baked at 100° C. for 2 minutes, therebyforming an actinic ray-sensitive or radiation-sensitive film having athickness of 22 nm.

The actinic ray-sensitive or radiation-sensitive film was irradiatedwith 101 mJ/cm² of light rays at a wavelength of 13.5 nm through apattern mask, using a lithographic processing system having an EUV lasersource (MET manufactured by Exitech Ltd., NA 0.3). After irradiation,the actinic ray-sensitive or radiation-sensitive film was post-exposurebaked (PEB) at 165° C. for 2 minutes. Using a puddle development method,the actinic ray-sensitive or radiation-sensitive film after PEB wasdeveloped with propylene glycol monomethyl ether acetate (PGMEA), rinsedwith deionized water, and finally heated at 200° C. for 5 minutes.

Examples 10 to 12

A pattern was obtained by the same method as in Example 9 except thatthe filtration method was changed to a method described in Table 1.

Example 13

A pattern was obtained by the same method as in Example 9 except thatthe solution of monobutyltin oxide (BuSnOOH) in 4-methyl-2-pentanol waschanged to a solution (0.025 mol/L) of dibutyltin diacetate inn-propanol.

Examples 14 to 16

A pattern was obtained by the same method as in Example 13 except thatthe filtration method was changed to a method described in Table 1.

Example 17

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to butyl acetate and the rinsing step wasremoved.

Example 18

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to isoamyl acetate and the rinsing step wasremoved.

Example 19

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to 2-heptanone and the rinsing step wasremoved.

Example 20

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to butyl acetate and the rinsing liquid waschanged to 4-methyl-2-pentanol.

Example 21

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to butyl acetate and the rinsing liquid waschanged to decane.

Example 22

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to isoamyl acetate and the rinsing liquid waschanged to undecane.

Example 23

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to isoamyl acetate and the rinsing liquid waschanged to 4-methyl-2-pentanol.

Example 24

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to isoamyl acetate and the rinsing liquid waschanged to di-n-butyl ether.

Example 25

A pattern was obtained by the same method as in Example 9 except thatthe developer was changed to isoamyl acetate and the rinsing liquid waschanged to decane.

Example 26

A pattern was obtained by the same method as in Example 5 except thatthe developer was changed to a 2.38%-by-mass aqueous tetramethylammoniumhydroxide (TMAH) solution including 1.0% by mass of KOH as an additive.

Comparative Example 1

A pattern was obtained by the same method as in Example 1 except thatthe filtration method was changed to the method described in Table 1which will be described later.

Comparative Example 2

A pattern was obtained by the same method as in Example 9 except thatthe filtration method was changed to the method described in Table 1which will be described later.

Comparative Example 3

A pattern was obtained by the same method as in Example 9 except thatthe filtration method was changed to the method described in Table 1which will be described later.

<Circulation Filtration Method>

[Filtration Device 1]

As shown in FIG. 1, a tank 1, a pump 2, and a column 100 with a firstfilter installed were connected to flow paths 5, 6, and 7. In the flowpath 7, a flow meter 3 and a filling port 8 were installed, and in acontainer 4 filled with a treatment liquid, a device capable of fillingan actinic ray-sensitive or radiation-sensitive composition aftertreatment was assembled. The pump 2 was driven such that a solution ofthe actinic ray-sensitive or radiation-sensitive composition containedin the tank 1 was circulated in a closed system in the order of the tank1, the pump 2, and the column 100.

Here, the number of circulations was defined as follows: [(Integratedamount of the solution of the actinic ray-sensitive orradiation-sensitive composition passing through the firstfilter)/(Amount of the solution of the actinic ray-sensitive orradiation-sensitive composition introduced into the tank)−1].

In Examples 1 to 5, 9 to 13, and 17 to 26, and Comparative Examples 1 to3, the filtration device 1 was used.

[Filtration Device 2]

As shown in FIG. 2, a tank 1, a pump 2, a column 100 with a first filterinstalled, and a column 200 with a second filter installed wereconnected to flow paths 5, 6, 7, and 9. In the flow path 7, a flow meter3 and a filling port 8 were installed, and in a container 4 filled witha treatment liquid, a device capable of filling an actinic ray-sensitiveor radiation-sensitive composition after treatment was assembled. Thepump 2 was driven such that a solution of the actinic ray-sensitive orradiation-sensitive composition contained in the tank 1 was circulatedin a closed system in the order of the tank 1, the pump 2, the column200, and the column 100.

Here, the number of circulations was defined as follows: [(Integratedamount of the solution of the actinic ray-sensitive orradiation-sensitive composition passing through the firstfilter)/(Amount of the solution of the actinic ray-sensitive orradiation-sensitive composition introduced into the tank)−1].

In Examples 6 to 8, and 14 to 16, the filtration device 2 was used.

<Resolving Power>

The resolution situations of 1:1 line-and-space patterns having linewidths of 20 nm, 18 nm, 16 nm, 15 nm, 14 nm, and 13 nm were observedusing a scanning electron microscope (S-938011 manufactured by HitachiLtd.). A case where the pattern is resolved without problems is denotedas A, and the other cases are denoted as B or C on the basis of thefollowing standard. Resolution of the pattern having a smaller sizeindicates better resolution performance.

A: Resolved

B: Partially not resolved (it is possible to measure the line width)

C: Not resolved (it is difficult to measure the line width)

<Residual Defects>

The pattern shapes of 1:1 line-and-space patterns with a line width of20 nm obtained by the method were observed by a scanning electronmicroscope (S-938011 manufactured by Hitachi Ltd.), and the number ofresidual defects was determined. While shifting the observation pointsby 1 μm, 1,000 sheets of photography were taken and the number ofresidual defects found on the pattern was counted. A smaller number ofresidual defects indicates better performance.

<Method for Measuring Particles in Liquid>

For the obtained actinic ray-sensitive or radiation-sensitivecomposition, the number (particles/mL) of particles having particlediameters of 0.15 μm or less in the actinic ray-sensitive orradiation-sensitive composition immediately after the preparationthereof was measured. For the measurement of the number of particles,the number was counted using a particle counter KS-41 manufactured byRion Co., Ltd.

The filtration method and the evaluation results of Examples andComparative Examples are shown in Table 1 below.

TABLE 1 Filtration method Evaluation results Materials Number NumberMaterials of second (particles/ (defects) Number of of first filter mL)of of circulations filter (pore (pore particles 20 nm 18 nm 16 nm 15 nm14 nm 13 nm residual (times) diameter) diameter) in liquid ResolutionResolution Resolution Resolution Resolution Resolution defects Example 12 Polyethylene None 10 A A A B B C 50 (50 nm) Example 2 4 PolyethyleneNone 8 A A A B B C 23 (30 nm) Example 3 9 Polyethylene None 6 A A A A BB 12 (10 nm) Example 4 29 Polyethylene None 2 A A A A A A 6  (5 nm)Example 5 2 Polyethylene None 1 A A A A A A 3  (2 nm) Example 6 4Polyethylene Nylon 6.6 4 A A A A A A 9 (10 nm) (20 nm) Example 7 9Polyethylene Nylon 6.6 1 A A A A A A 3  (5 nm) (20 nm) Example 8 29Polyethylene Nylon 6.6 0 A A A A A A 0  (2 nm) (20 nm) Example 9 2Polyethylene None 9 A A A B B C 48 (50 nm) Example 10 4 PolyethyleneNone 7 A A A B B C 32 (30 nm) Example 11 9 Polyethylene None 6 A A A A BB 25 (10 nm) Example 12 29 Polyethylene None 2 A A A A A A 10  (5 nm)Example 13 2 Polyethylene None 0 A A A A A A 4  (2 nm) Example 14 4Polyethylene Nylon 6.6 3 A A A A A A 9 (10 nm) (20 nm) Example 15 9Polyethylene Nylon 6.6 1 A A A A A A 2  (5 nm) (20 nm) Example 16 29Polyethylene Nylon 6.6 0 A A A A A A 1  (2 nm) (20 nm) Example 17 2Polyethylene None 9 A A A A B C 42 (50 nm) Example 18 2 PolyethyleneNone 9 A A A A B B 39 (50 nm) Example 19 2 Polyethylene None 9 A A A B BC 45 (50 nm) Example 20 2 Polyethylene None 9 A A A A B C 44 (50 nm)Example 21 2 Polyethylene None 9 A A A A B B 42 (50 nm) Example 22 2Polyethylene None 9 A A A A A B 40 (50 nm) Example 23 2 PolyethyleneNone 9 A A A A B B 48 (50 nm) Example 24 2 Polyethylene None 9 A A A A BB 45 (50 nm) Example 25 2 Polyethylene None 9 A A A A A B 40 (50 nm)Example 26 2 Polyethylene None 1 A A A A B B 10  (2 nm) Comparative 0Polyethylene None 50 A A B C C C 432 Example 1 (50 nm) Comparative 0Nylon 6.6 None 100 A C C C C C 750 Example 2 (40 nm) Comparative 1 Nylon6.6 None 55 A B C C C C 450 Example 3 (40 nm)

The actinic ray-sensitive or radiation-sensitive compositions ofExamples 1 to 26 were obtained after performing circulation filtrationusing a filter of a polyethylene-based resin. The number of particles inliquid having particle diameters of 0.15 μm or less included in 1 mL ofthese actinic ray-sensitive or radiation-sensitive compositions was 10or less, the resolution was good and there were few residual defects. InComparative Example 1, filtration was performed using a filter of apolyethylene-based resin, circulation filtration was not performed, andthe number of particles in liquid having particle diameters of 0.15 μmor less included in 1 mL of the composition was 50. In addition, inComparative Example 2, the filter of a polyethylene-based resin was notused, and the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the composition was 100. InComparative Examples 1 and 2, the resolution was deteriorated, and therewere more residual defects than in Examples.

In Examples 9 to 25 (organic solvent development), the same effects wereobtained even with a liquid obtained by mixing two or more of theliquids described in the specification as the developer or the rinsingliquid.

The same effects were obtained even with the addition of at least oneselected from the basic compound, the ultraviolet absorber, thesurfactant, and the other additives described in the specification tothe actinic ray-sensitive or radiation-sensitive compositions used inExamples.

EXPLANATION OF REFERENCES

-   -   1: tank    -   2: pump    -   3: flow meter    -   4: container filled with treatment liquid    -   5, 6, 7: flow paths    -   8: filling port    -   100: column with first filter installed    -   200: column with second filter installed

What is claimed is:
 1. An actinic ray-sensitive or radiation-sensitivecomposition comprising: a cation including a metal atom; and a ligand,wherein the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition is 10 or less.
 2. The actinicray-sensitive or radiation-sensitive composition according to claim 1,wherein the actinic ray-sensitive or radiation-sensitive compositioncontains a suboxide cation of a metal atom, a counter anion, aperoxide-based ligand, and water.
 3. The actinic ray-sensitive orradiation-sensitive composition according to claim 1, wherein theactinic ray-sensitive or radiation-sensitive composition contains thecation including a metal atom, an organic ligand, and an organicsolvent.
 4. The actinic ray-sensitive or radiation-sensitive compositionaccording to claim 1, wherein the metal atom is at least one selectedfrom hafnium, zirconium, and tin.
 5. The actinic ray-sensitive orradiation-sensitive composition according to claim 1, wherein the metalatom is at least one selected from hafnium and zirconium.
 6. The actinicray-sensitive or radiation-sensitive composition according to claim 1,wherein the metal atom is tin.
 7. A method for purifying an actinicray-sensitive or radiation-sensitive composition, comprising subjectinga solution of an actinic ray-sensitive or radiation-sensitivecomposition containing a cation including a metal atom and a ligand tocirculation filtration using a filter of a polyethylene-based resin,wherein the number of particles in liquid having particle diameters of0.15 μm or less included in 1 mL of the actinic ray-sensitive orradiation-sensitive composition after the circulation filtration is 10or less.
 8. The method for purifying an actinic ray-sensitive orradiation-sensitive composition according to claim 7, wherein thecirculation filtration is performed using a filter of a polyamide-basedresin in combination with the filter of a polyethylene-based resin. 9.The method for purifying an actinic ray-sensitive or radiation-sensitivecomposition according to claim 8, wherein a pore diameter of the filterof a polyethylene-based resin is 10 nm or less.
 10. The method forpurifying an actinic ray-sensitive or radiation-sensitive compositionaccording to claim 7, wherein a pore diameter of the filter of apolyethylene-based resin is 10 nm or less.
 11. A pattern forming methodcomprising the method for purifying an actinic ray-sensitive orradiation-sensitive composition according to claim
 7. 12. A method formanufacturing an electronic device, comprising the pattern formingmethod according to claim 11.